[Heathkit] Heathkit VHF Wattmeter with manual $40

[Glen Zook]

Well, yes and no.  If you use the internal calibration feature to calibrate the wattmeter then C2 is changed from 12 pf to 14 pf depending on the band.  However, the basic calibration of the wattmeter is still good from 50 MHz to 160 MHz if you use an external standard such as a Bird wattmeter.  Also, unless the actual capacitor that came with the wattmeter was very close tolerance, with a normal +/- 10% component the tolerance overlap could actually put these calibration capacitors on the opposite side of the calibration curve from where they are supposed to be.

This per the manual on the HM-2102 which is the single meter version.  I don't have a Heath HM-2141, the two meter version, but supposedly the basic circuitry is the same.

Glen, K9STH

Website:  http://k9sth.com


--- On Tue, 11/30/10, Van K7VS <wa7fab at cdsnet.net> wrote:

> From: Van K7VS <wa7fab at cdsnet.net>
> Subject: Re: [Heathkit] Heathkit VHF Wattmeter with manual $40
> To: "Glen Zook" <gzook at yahoo.com>, heathkit at mailman.qth.net, "john" <johnmb at nc.rr.com>
> Date: Tuesday, November 30, 2010, 11:39 AM
> well i can't dispute what you say
> glen other than to tell you we are in portland, 
> waiting for our flight to the barbados.  i have two
> units, one set up for six and the other for two
> meters.  they are single meter units and in the old
> heath green color inclosures with a meter same size and
> design as we see on the sb-200 linear.  they do require
> changing parts for switching vhf bands.  which ones are
> sitting in my shop, glen?   i can't remember
> the nominclature.  van 
>